coal bunker into dog house

ocallagh

I'm adapting a coal bunker and turning it into a dog house. I'm relatively inexperienced at DIY, especially roofing etc.

The coal bunker sits at the back of a car port. The roof of the car port is covered with corrugated iron which slopes down towards the coal bunker, so the coal bunker constantly fills with water right now. I'm proposing to fit a wooden framed roof at 30 degrees, covered with roofing material such as mineral roofing. The roof will be on a hinge at the back so I can lift it to clean out the dog house.

My question is, how can I seal the back of the construction from water seeping down the concrete wall? Also, it is very windy, so water could easily be pushed up the 30 degree slope and down the back of the construction. See red dot in attached picture.

Is it possible to attach something to the concrete wall, like rubber flaps (think mudflaps for a car or similar) or maybe even attach some more mineral roofing to the concrete wall and have that overhang onto the roof??? Any suggestions?

ocallagh

for anyone interested, I found an answer here http://en.allexperts.com/q/Building-Homes-Extensions-2333/2009/2/Flashing-Shed-Roof-against-2.htm or here http://www.diynot.com/forums/viewtopic.php?t=169201

I need to cut a strip out of the cement, which will allow me to place flashing along it and re-cement it up, giving me the overhang I need.